The use of foldable and portable flexible barriers to arrest the flight of golf balls hit in practice is well known. The structure and configuration of the barriers varies widely, as shown in the disclosures of the following patents which are considered exemplary of the prior art:
__________________________________________________________________________ U.S. Pat. No. ISSUE DATE INVENTOR TITLE __________________________________________________________________________ 1,173,262 Feb 29, 1916 Gunzburg APPARATUS FOR USE IN PRAC- TICING THE GAME OF GOLF 1,218,390 Mar 6, 1917 Gates PRACTICE DEVICE FOR GOLF AND LIKE OUTDOOR GAMES 1,669,640 May 15, 1928 Warlick INDOOR GOLF 3,390,882 July 2, 1968 Megerle PORTABLE GOLF DRIVING RANGE INCLUDING HINGE MEANS CONNECTING SELF-SUPPORTING PANELS 3,643,959 Feb 22, 1972 Cornell GOLF GAME 3,895,809 July 22, 1975 Shockley BALL RETURN DEVICE 4,381,110 Apr 26, 1983 Balaz GOLF TRAINER DEVICE 4,556,219 Dec 3, 1985 Tillery GOLF PRACTICE CAGE 4,703,931 Nov 3, 1987 Steen APPARATUS FOR RETURNING OR REBOUNDING A BALL 4,883,272 Nov 28, 1989 Lay BALL CATCHING MACHINE WITH BALL EXPELLING MACHINE CONNECTED THERETO 4,969,651 Nov 13, 1990 Comartin FLEXIBLE PROJECTILE AR- RESTING DEVICE 5,018,731 May 28, 1991 Doyle GOLF BALL DRIVING PRACTICE APPARATUS __________________________________________________________________________
Several of the foregoing patents rely on flexible netting to arrest the flight of the ball. See, for example, U.S. Pat. No. 4,381,110 to Balaz, U.S. Pat. No. 4,556,219 to Tillery, U.S. Pat. No. 4,703,931 to Steen, U.S. Pat. No. 4,883,272 to Lay, and U.S. Pat. No. 4,969,651 to Comartin.
The use of a stiffer fabric, such as canvas, to absorb the direct impact of the ball and thereby arrest its flight is shown in U.S. Pat. No. 1,218,390 to Gates, U.S. Pat. No. 3,895,809 to Shockley, and U.S. Pat. No. 5,018,731 to Doyle.
U.S. Pat. No. 1,173,262 to Gunzburg discloses a circular metal race. Gunzburg's race does not arrest the flight of the ball. Instead, the distance which a ball travels along the race, or the number of times the ball travels around the race is a measure of the length of the stroke.
The prior art discloses several ways to rely on the force of gravity to return the ball to the person practicing golf. Gravity causes the ball to stop at the bottom of Gunzburg's race, which is spaced a short distance from the entrance d of Gunzburg's funnel c. Gravity causes the ball to roll toward the user along the inclined lower wall 2 of Gates' sack; along the inclined lower wall 18 of Megerle's driving range; along the inclined lower wall 15 of the Balaz device; along the concave canvas member 24 of Shockley; along the inclined floor 22 of Tillery; along the inclined bottom wall 26 of Steen; and along the inclined return channel 82 of Doyle. Gravity directs the balls along the inclined pan 17 of Warlick and into the inclined return pipe 18 which empties into a box-like rack 19 on the tee.
Shockley and Doyle disclose target areas (28 and 56, respectively) that are substantially perpendicular to the path of the ball.